Winding shaft with variable torque

ABSTRACT

An apparatus for winding bands on to cylindrical supports, comprises a rotatable shaft having a plurality of winding sleeves each being adapted to carry a support and cause it to rotate with the sleeve, each sleeve being independently rotatable on the shaft. Associated with each sleeve is a friction drive from the shaft and means for adjusting the torque applied to the sleeve.

United States Patent Jiires et al.

[ Nov. 25, 1975 Germany Assignee: Agfa-(Jevaert Aktiengesellschaft,

Leverkusen, Germany Filed: Apr. 20, 1973 Appl. Nov 352.965

Published under the Trial Voluntary Protest Program on January 28, I975 as document no 8 352.965.

Foreign Application Priority Data Apr 25 I972 Germany. 2220l59 U.S. Cl. i i v i i i a i i i .7 242/563 Int. Cl. i i v v i l l v i i B65" 19/04 Field of Search i i a 242/569 75.5. [56,2

[56] References Cited UNITED STATES PATENTS 2,43l,l3() ll/l947 Luchonsky ,7 242/569 3322,36] 5/]967 Young i t i 242/569 3.622096 ll/l97l Young t t i v i 242/569 3,669.36) 6/l972 Emichmmmw i 7 242/569 3.702687 ll/l972 Hall i a i i a v v. 2-42/569 Primary ExaminerEdward J. McCarthy Atlorney. Agent or Fr'rmConnoll v and HutZ [57] ABSTRACT An apparatus for winding bands on to cylindrical supports comprises a rotatable shaft having a plurality of winding sleeves each being adapted to carry a support and cause it to rotate with the sleeve, each sleeve being independently rotatable 0n the shaft Associated With each sleeve is a friction drive from the shaft and means for adjusting the torque applied to the sleeve.

9 Claims, 2 Drawing Figures U.S. Patent Nov. 25, 1975 Sheet 1 of2 3,921,926

ON m

US. Patent Nov. 25, 1975 Sheet 2 of2 3,921,926

WINDING SHAFT WITH VARIABLE TORQUE This invention relates to a winding shaft for winding bands. comprising a plurality of winding sleeves arranged along the shaft. which sleeves are individually driven by friction drives. Winding shafts of this kind are used. for example. for winding bands which have been cut on a roll cutting machine on to winding sleeves or cores. for example in commonly assigned U.S. Pat. application Ser. No. 318.2l I. filed Dec. 26. I972. The finished packages should be of uniform diameter and wound at a constant tension.

Winding shafts have been described for this purpose in which the torque of the shaft is increased with iricreasing diameter of the roll by electrical means (direct current motor). In this arrangement. all the bands are wound at the same speed of rotation. in other words the rolls are not driven individually by friction.

Other winding shafts are known which are driven at a regulated speed of rotation and in which the torque is adapted to the increasing diameter of the rolls by individual friction drives. This type of winding shaft has the disadvantage that the contact pressure force of the individual friction drives is transmitted from one end of the shaft to the other through all the friction and sleeve clamping elements so that a considerably proportion of the driving force is lost in friction. Consequently, differing frictional forces are produced which adversely affect the winding characteristic.

It has been found in practice that when a wide web of paper is separated into individual bands. the lengths of the bands differ slightly from each other. These differ ences in length are due to so-callcd web lobes which are formed e.g. by one-sided stretching or shrinkage of the web or uneven uptake of moisture or uneven drying. When the individual bands are wound on a continuous winding shaft, these differences in length result in differing tensions in the band. The rolls obtained by winding the bands then have differing winding characteristics. In the worst cases. this may interfere with sub sequent operations, especially if. for example, the rolls are wound too loosely.

It is therefore not sufficient to drive the winding shafts at a regulated speed of rotation as is the case in known winding shafts which are driven by a direct current motor. Instead. all the rolls of the winding shaft must be provided with separate friction means. The winding shaft must therefore have a certain forward slip to compensate for the different tensions of the bands. If the final diameter of the wound roll is a multiple of its initial diameter. then the individual friction drives which are calculated according to the torque are no longer sufficient because the tension with which they wind the bands decreases with increasing diameter of the rolls so that the required winding characteristic is not fulfilled. The winding shafts previously used are therefore not suitable for winding bands with different tensions.

The object of this invention is the construction of a winding shaft for such bands with differing tensions.

For a winding shaft with individual frictions. the invention solves this problem by means of the fact that the flow of force of the friction drives and hence the torque which can be transmitted to the winding sleeves is adjustable from outside. To ensure a constant ten sion. therefore. the torque of the individual friction drives is continuously increased in accordance with the 2 increasing diameter of the rolls during operation of the machine.

According to one advantageous embodiment of the invention. the winding sleeves carry friction discs at their end faces. These friction discs are pressed against the adjacent discs of the friction heads which are fixed on the shaft. and the contact pressure is adjustable by means of a pull exerted on the friction heads in the axial direction.

According to one embodiment of the invention which has proved to be particularly suitable. the friction heads are connected to an axial ball bearing by rails or wires extending in grooves along the shaft. This axial ball bearing is displaccable in the axial direction to adjust the required contact pressure.

The shaft is advantageously mounted in a fork head which is displaceable in the axial direction and which transmits the force required to adjust the contact pressure directly to the fixed part of the radial ball bearing. The movement of this fork head is initiated by control elements of known construction.

According to further feature of the invention. each friction head is composed of a friction disc. :1 pressure spring and a moveable and a fixed cover plate. and the bias tension of the pressure spring is adjustable by means of setting screws so that the friction heads are elastic in the axial direction with variable bias tensions. This special construction of the friction heads enables the friction pressures to be adjusted individually. The friction heads also serve to compensate for stretching in the wires or rails used for transmission of the force.

According to another improvement of the invention. at least two pivotal rocker arms are provided for each winding sleeve. These rocker arms have a wedge shaped surface and therefore yield resiliently when the winding sleeves are pushed over them. When the winding sleeves have passed over the rocker arms. the arms are deflected completely outwards by the spring force and form an unshiftable abutment for the winding sleeves. The rocker arms can also be swung back by actuating a pushrod with coneshaped element mounted inside the winding shaft and they can be sunk into recesses in the winding shaft. The winding sleeves are then released. These abutments which can be swung in or out considerably facilitate mounting of the winding sleeves on the shaft.

It has been found that the winding shaft described above satisfies all the requirements in practice. Even bands obtained from badly lobed webs can be wound up into rolls which are uniform in diameter and tension. The winding shafts previously used are unsatisfactory for this purpose.

An example of the invention will now be described in detail with reference to the drawing in which FIG. I is a cross sectional longitudinal view of on em bodiment of this invention taken through FIG. 2A-B and in FIG. 2C-D along the lines l1 FIG. ZA-B is a cross sectional view taken through FIG. I along the line ZA-ZB; and FIG. 2C-D is a cross sectional view taken through FIG. 1 along the line 2C-2D.

With reference to all of the figures of the drawing. winding shaft according to FIG. I consists of a hollow cylinder 1 with winding sleeves 2 and friction heads 3. Inside the hollow cylinder is a pushrod 4 for actuating the rocker arms 5. The rocker arms 5 serve as abutments for the winding sleeves 2 which are arranged at regular intervals along the winding shaft. The winding sleeves 2 are mounted on so-called sleeve holders 2a. These sleeve holders 2a are mounted to be rotatable b, means of ball bearings 6 and carry friction discs 7 at one end. The winding sleeve 2 with counterplate 8 rigidly connected to it is pressed between these friction discs 7 in cooperation with inner counterplate 80 secured to hollow shaft 1 by pin 8b. The friction head is a spring element. lt essentially comprises the spring 9. movable cover plate 10 and outer cover plate ll. The outer cover plate ll carries setting screws I 10 for varying the bias tension of spring 9. The pressure springs 9 determine the initial torque of the sleeve holders so that small rolls can also be wound without readjustment of the torque. Drawing wires 12 are arranged parallel to the axis on the cover plate 11 of the winding heads 3. They lie in grooves along the shaft and are connected to the axial ball bearing 13. Axial displacement of the axial ball bearing 13 changes the tension transmitted to the friction heads by the drawing wires and hence also the friction pressure and the torque. At least two drawing wires must be provided for symmetry. The drawing wires are mounted in a displaceable fork head 14. The movement of this fork head is transmitted directly to the fixed part of the axial ball bearing 13 and can be adjusted according to the increasing diameter of the rolls by means of a governor circuit. The torque transmitted from the friction heads 3 to the winding sleeves therefore increases with increasing diameter of the rolls. When the contact pressure disappears, the torque transmitted is zero. Owing to the ball bearing 6, the sleeve holders are at rest while the friction heads 3 and drawing wires 12 rotate.

The adjustable friction heads have the further advan tage that the friction properties can be adjusted individually for each winding sleeve and that stretching of the drawing wires can be compensated.

As already mentioned above. the rocker arms 5 which serve as abutments for the winding sleeves are controlled by the movement of the pushrod 4. The pushing movement is initiated by a compressed air driven piston (not shown) by way of an entrained coupling ring 15 and the coupling fork l6. The pushrod 4 has a cone shaped element 17 in the position of each rocker arm for transmitting the movement to the rocker arm. The spring 18 exerts an opposing force on the rocker arm 5. The rocker arm 5 is rotatably mounted about the pivot 19 and when swung inwards it disappears into the recess 20 of the winding shaft. The rocker arm 5 has a chamfered surface 21 at its outer end. When the empty winding sleeves 2 are pushed on to the winding shaft from the left, the chamfered surface 21 of the rocker arm 5 slides over the inner surface of the winding sleeve until the left end is reached. Owing to the opposing force of the spring 18, the rocker arm 5 then snaps out and forms an immovable abutment for the winding sleeve. When winding of the rolls is finished, the pushrod 4 is actuated to the left). The rocker arm 5 then folds in and the rolls can be removed from the winding shaft. The time required for mounting a fresh set of sleeves can be considerably reduced in this apparatus.

What we claim is;

1. Apparatus for winding bands on to cylindrical tu bular supports. comprising a rotatable shaft having a plurality of winding sleeves each having a cylindrical surface adapted to carry a cylindrical tubular support and cause it to rotate with the sleeve. each sleeve being independently rotatable on the shaft and. associated with each sleeve. a friction drive from the shaft and means for adjusting the torque applied to the sleeve by the friction drive.

2. An apparatus as claimed in claim I in which each sleeve carries a first friction disc which reacts in the direction of a second friction disc. the second friction disc not being capable of rotation with respect to the shaft but being moveable along the axis of the shaft so that the contact pressure between the first and second friction discs can be varied to adjust the torque applied to the sleeve. and means for moving the second friction disc along the axis of the shaft.

3. An aparatus as claimed in claim 2 in which the means for moving the second friction disc comprises axial elements connecting the friction disc to a ring bearing also mounted on the shaft, the ring bearing receiving a forked control head which can be moved in an axial direction to vary the contact pressure between the friction discs.

4. An apparatus as claimed in claim 3 in which the said axial elements are disposed within the sleeve and are received in axial grooves in the shaft.

5. An apparatus as claimed in claim 3 in which spring pressure means are interposed between the axial elements and the second friction disc which tend to increase the contact pressure against the friction discs, and the spring pressure means are adjustable.

6. An apparatus as claimed in claim 5 in which each sleeve has associated therewith retaining means which allow the supports to be mounted on the sleeve by sliding them in a first direction and then retains the supports on the sleeve and prevents them from sliding off in an opposite direction and means for releasing the retaining means.

7. An apparatus as claimed in claim 6 in which the said retaining means comprises one or more spring biased catches which can be released by operating of a rod mounted inside the shaft.

8. An apparatus as claimed in claim 3 wherein a counterplate is mounted within the sleeve in contact with the second friction disc. the counterplate being connected to the sleeve between the two friction discs whereby movement of the ring bearing against the first friction disc compresses the headplate between the two friction discs.

9. An apparatus as set forth in claim 8 where an inner counterplate is connected to the shaft. a yieldable catch maintains the sleeve longitudinally positioned on the shaft whereby the axial movement of the sleeve by the ring bearing moving towards it and the first friction disc causes the counterplate to compress the second friction disc against the inner counterplate attached to the shaft. 

1. Apparatus for winding bands on to cylindrical tubular supports, comprising a rotatable shaft having a plurality of winding sleeves each having a cylindrical surface adapted to carry a cylindrical tubular support and cause it to rotate with the sleeve, each sleeve being independently rotatable on the shaft and, associated with each sleeve, a friction drive from the shaft and means for adjusting the torque applied to the sleeve by the friction drive.
 2. An apparatus as claimed in claim 1 in which each sleeve carries a first friction disc which reacts in the direction of a second friction disc, the second friction disc not being capable of rotation with respect to the shaft but being moveable along the axis of the shaft so that the contAct pressure between the first and second friction discs can be varied to adjust the torque applied to the sleeve, and means for moving the second friction disc along the axis of the shaft.
 3. An aparatus as claimed in claim 2 in which the means for moving the second friction disc comprises axial elements connecting the friction disc to a ring bearing also mounted on the shaft, the ring bearing receiving a forked control head which can be moved in an axial direction to vary the contact pressure between the friction discs.
 4. An apparatus as claimed in claim 3 in which the said axial elements are disposed within the sleeve and are received in axial grooves in the shaft.
 5. An apparatus as claimed in claim 3 in which spring pressure means are interposed between the axial elements and the second friction disc which tend to increase the contact pressure against the friction discs, and the spring pressure means are adjustable.
 6. An apparatus as claimed in claim 5 in which each sleeve has associated therewith retaining means which allow the supports to be mounted on the sleeve by sliding them in a first direction and then retains the supports on the sleeve and prevents them from sliding off in an opposite direction and means for releasing the retaining means.
 7. An apparatus as claimed in claim 6 in which the said retaining means comprises one or more spring biased catches which can be released by operating of a rod mounted inside the shaft.
 8. An apparatus as claimed in claim 3 wherein a counterplate is mounted within the sleeve in contact with the second friction disc, the counterplate being connected to the sleeve between the two friction discs whereby movement of the ring bearing against the first friction disc compresses the headplate between the two friction discs.
 9. An apparatus as set forth in claim 8 where an inner counterplate is connected to the shaft, a yieldable catch maintains the sleeve longitudinally positioned on the shaft whereby the axial movement of the sleeve by the ring bearing moving towards it and the first friction disc causes the counterplate to compress the second friction disc against the inner counterplate attached to the shaft. 